Geberit 111.335.00.5 DuoFix In-Wall System with Sigma Concealed Tank for 2x6 Wall Construction Provides clean and modern finish with no visible pipe work For installation in wood or steel stud walls that provide support equal to 2-inch by 6-inch (5.5-inch) depth For 2-hole wall-hung wash-down WC with 7.1-inch or 9.1-inch fastening distance Fits15-inch to19-inch toilet heights 1.6 GPF, supports up to 880 pounds